Answers for "String Contains All Binary Codes of Size K"

how to remove maximum number of characters in c++ cin,ignore

std::cin.ignore(std::numeric_limits<std::streamsize>::max(), 'n');

c# max sequence contains no elements

return collection.Any() ? collection.Max(c => c.Value) : 0;
// Or replace 0 with null or whatever other default 
// value you'd like to return.